Indivisible by Two: Lives of Extraordinary Twins by Nancy L. Segal

by Nancy L. Segal

A leading expert on twins delves into the stories behind her research to reveal the profound joys and real-life traumas of twelve remarkable sets of twins, triplets, and quadruplets.Indivisible by Two introduces us to an assortment of memorable characters, from the "Fireman Twins"--brothers who, though reared separately, are astonishingly similar in personality and behavioral traits--to the twin sisters who overcame one twin's infertility by having the other serve as her surrogate mother. We meet one of the few identical brother-sister pairs in the world after one of two sisters was surgically transformed into a man, and identical triplet brothers, only one of whom is gay while the others are straight. We see uniquely blended families--identical twin brothers marrying identical twin sisters, and Chinese twins adopted by different Canadian families yet raised as sisters.Being a twin can also render the experience of historical tragedy uniquely painful. We meet Stepha and Annetta, survivors of Josef Mengele's heinous experiments in Auschwitz, and untangle the troubled lifelong tie between Jack and Oskar, born in the 1930s to a Jewish father and a German Gentile mother, one raised as a Jew in Trinidad and the other as a Catholic and a member of the Hitler Youth in Nazi Germany.Segal unravels these stories and others with an eye for the challenges that life as a twin (or triplet or quadruplet) can pose to parents, friends, and spouses, as well as the twins themselves. These moving stories remind us how incompletely any theory explains real life--twin or not.

Genres: Nonfiction, Psychology, Science, Sociology

Paperback

First published January 1, 2005

About the author

I am a Psychology Professor at California State University, Fullerton, with a special interest in twin studies--I am a fraternal twin myself! I have always been fascinated with the differences between my sister and myself, as well as the similarities and differences between identical twins. My career has been informative, and so much fun! And I am very excited about my recent books.

When I am not being an academic you can find me swing dancing or watching old films.

Reviews

[Barbara (Bobby) Title · Rating 4 out of 5]

A month or so ago the LA Times carried a large obituary for Oskar Yufe, the German half of the Oskar/Jack twins. In this obit there was a reference to Nancy L. Segal's book and I couldn't wait to find and read the book. Segal is a noted twin-researcher, and what delighted me is that the book was not chock-full of theories and statistics on twins but of very warm and personalized vignettes of the twins or multiples, their families, and of her interaction with them. There was no dry stuff here. Her writing took me with her through some very fascinating and eye-opening contacts.

I am not a twin, nor are there twins in my family, but to me this book was as interesting as if there were. The important thing is that each set of multiples was different, very different from all the other sets, so every chapter was new and drew me in all over again.

It's not often an obituary causes me to go after a good book, but this one sure did!

[dejah_thoris · Rating 4 out of 5]

Of the three books of Segal's I'm reading, this is the one I'd recommend. It's a layperson friendly version of Entwined Lives that has a little science, but mostly focuses on the twins' biographies. There's also only one brief section that needed an adoption trigger warning on pages 180-181. (It describes celebrating Gotcha Day and negates the need for international adoptees to know the circumstances of their birth and surrender provided they are exposed to their cultural heritage through trips, community programs, etc. Personally, I think all that does is assuage our first-world guilt over importing babies because it takes "too long" or is "too expensive" to adopt American children in need.)

[manatee · Rating 4 out of 5]

An utterly compelling and fascinating work about multiples. Some of the stories were slightly familiar, but most of the situations profiled here were completely new to me.
I was especially fascinated by the stories of twins who were married to twins(Quaternary marriage), but each chapter in this book is a revelation. I highly recommend it to anyone interested in learning more about multiples.
By the way, I found this book in the freebie pile of the Book Cellar in the library where I work. I find such gems there.

[Anna Harrison · Rating 4 out of 5]

This was a really interesting read for many reasons - psychology, genetics, and child development. The wording and some of the perspectives feel outdated reading this in 2025 but that's to be expected with 20 years difference.

[Sheela Word · Rating 4 out of 5]

Interesting and informative book about various sets of identical twin. Case studies.

[Susan · Rating 4 out of 5]

Very interesting book…some very sad stories, some very happy. I’m glad I read it.

[Christine · Rating 4 out of 5]

From a scientific standpoint, as expected, well written and researched. From a human standpoint, there were many surprises in how individual sets of twins and their families reacted to each other and their life and family situations. I think most of us have expectations based on our own experience. However, our own experience does not often provide us with the background to easily interpret another culture or time period. Equally difficult to "read" would be being dropped into another political environment vastly different from what we have known.

It seems that the culture between identical twins is an entity with which I have no experience and will probably never understand fully. Their special closeness, ability to interpret each other's moods and needs, and unconscious or subconscious mirroring of each other's activities and thoughts seems way beyond what I have known with siblings or other close relationships. I was surprised that the adult twin relationships seemed to override, or to at least some degree, exclude a spouse.

The closeness seems to work well for many twins in that it provides them with the support and companionship which they might not otherwise have. But the dynamic seems to also have some built-in limiting factors to it which in some twin relationships seems to be advantageous to one twin but limiting to the other.

The wide range of what twin relationships can be, how they work well between the twins or are more problematic, whether they are easily integrated into the existing family dynamic, and to what degree genetic or environmental factors have had effect on their relationships, and many other issues, are all explored in this book clearly and efficiently. I think the topic is covered with a satisfying degree of detail in a very readable style which does not feel merely clinical but seems to be genuinely concerned with the individual personalities and motives intended.

This book seems to me to be very enlightening to someone with little experience with the topic, and is an easy enjoyable read.

[Harvey · Rating 4 out of 5]

- Dr. Segal is Distinguished Professor of Humanities and Social Sciences and Director of the Twin Studies Center at California State University
- from the jacket: "A gripping collection of vignettes on an eternally fascinating phenomenon. Indivisible By Two is a wonderful book for its scientific implications, its human interest, and its literary quality."
- a globally-recognized expert on twins delves into the stories behind her research to reveal the profound joys and real-life traumas of twelve sets of twins, triplets, and quadruplets." "Indivisible By Two introduces us to an assortment of memorable characters, from the 'Fireman Twins' - brothers who, though raised entirely separately, are astonishingly similar is personality and behavioural traits - to the twin sisters who overcame one twin's infertility by having the other serve as her surrogate mother. We meet one of the few identical brother-sister pairs in the world after one of the sisters was surgically transformed into a man, and identical triplet brothers, only one of whom is gay while the others are straight."
- fascinating, well written

[Elizabeth T · Rating 3 out of 5]

I was inspired to read this book because my mom is a twin, and I found the topic interesting after reading a copy of National Geographic exploring the lives of twins. This book encounters different stories of twins around the world. It describes the deep connections between twins when in some cases, they aren't even raised together. Each section takes on a new set of twins, and even triplets and their stories. My favorite was an account of an identical set of twins, who happen to be a boy and a girl, after a sex-change surgery one of the two sisters decided to become a man. I thought all of the stories were very interesting and I recommend this book to anyone.

[Staci · Rating 5 out of 5]

As a mother of twins I am fascinated by the twin connection. This is fun and interesting book about twins (and a few other sets of multiples)in all sorts of situations like: raised apart, unusual circumstances, etc. The author is a twin herself and a leading researcher on twins. She writes a down-to-earth book that is easy to read and enjoyable. The stories will fascinate you and make you appreciate the special bond that twins share.

[Maura White · Rating 3 out of 5]

Despite my 3 stars, I thought it was a good book for twin parents and twins. Like other reviewers, I thought it was written in a very dry analytical style. The style didn't bother me for the first 1/2 of the book, but then I found that the writer was repeating herself and I was longing for the other books in my que.

[Mshopsin · Rating 3 out of 5]

I wish the women who wrote this book was not a doctor! It leads to very interesting stories that are somewhat clinical. I wish Nancy Segal the twin came out more in this book. Still a super and intriguing read.

[Shannon · Rating 2 out of 5]

This was just an interesting book about twins, their genetics, their propensities, their likenesses, and their differences. I enjoyed reading it because I'm intrigued by how we all become who we are and studying multiple births provides insights otherwise not available.

[Melanie · Rating 2 out of 5]

Truth be told, I didn't actually finish this one. Enjoyed the stories about twin ESP, twins separated at birth, etc., but just lost interest after awhile. I imagine someone who was really interested in studying identical twins would find this fascinating though.

[Charlotte · Rating 5 out of 5]

I found this book very interesting and think I will probably read more books about twins by this author. I thought the sentence structure could have been improved at times to make the information easier to understand, but the book was definitely worth reading.

[Jana · Rating 5 out of 5]

Really interesting read! I first heard about Nancy Segal on Australia's TV program, Insight, an episode about twins 10 years ago. A new twin episode was recently shown which prompted me to search for her books! Fascinating stuff!

[Alexis · Rating 3 out of 5]

This was a spontaneous choice that I just saw at the library and picked up. It is the true stories of remarkable sets of twins, or triplets, or quads. Interesting study in nurture vs nature.

[Becky · Rating 4 out of 5]

A more in-depth look at some of the people Segal interviewed for twin studies.

[Rebekah · Rating 3 out of 5]

I guess I was hoping it would be more about interesting research findings, and the anecdotes would be more illustrative than focal.

[Melanie · Rating 4 out of 5]

If you are a twin, parent or sibling of twins, this is a must-read.